1. Field of the Invention
Embodiments of the present disclosure relate generally to power line communications and, more particularly, to an apparatus for providing communication over power lines.
2. Description of the Related Art
Power Line Communications (PLC) is a technology for utilizing power lines, such as the existing commercial AC power grid infrastructure, to communicate data between devices coupled to the power lines. PLC typically operates in a point-to-multipoint fashion where one transmitter at a time transmits over the power line while other devices coupled to the power line receive the transmitted signal.
For PLC transmission, a transmitter is generally coupled to the power line through an isolation transformer and sends a voltage stimulus on the power line (i.e., a voltage-based signal) in accordance with relevant standards for PLC, such as BS EN 50065-1:2001 “Specification for Signaling on Low-Voltage Electrical Installations in the Frequency Range 3 kHz to 148.5 kHz”. These relevant standards set forth specifications for PLC operation, such as a maximum voltage level. As a result of power lines having undefined and variable impedances within the frequency band of interest for PLC, a transmitter module may be required to generate a large amount of current, for example on the order of hundreds of milliamperes, in order to meet the PLC voltage requirements.
Generally, PLC transmitters use linear amplifiers to achieve the required amplification and signal processing for PLC transmission. However, such devices dissipate high levels of power when operating to drive large currents on the power line and thus decrease the efficiency of the PLC transmitters. Additionally, the PLC transmitters generally perform filtering prior to the power amplification in order to satisfy spectral purity requirements set forth in the relevant standards, requiring a large number of costly components.
For receiving data transmitted over the power line, a PLC receiver is typically also coupled to the power line through an isolation transformer. The PLC receiver is required to provide a large input impedance to limit noise from the power line into the receiver prior to amplification, thereby requiring a costly number of components to perform such functions.
Therefore, there is a need in the art for an apparatus for efficient power line communications.